Did the Sun kill off Mars?????

[3488]

Very interesting article.<br /><br />After the collapse of the Martian magnetosphere & decline of volcanic activity, it<br />looks like the Sun spelt the death knell, for the Red Planet.<br /><br /> Did the Sun kill off Mars???<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[vandivx]

that sounds sort of like scientists who today ring bells saying we are (on the brink) destroying planet Earth altough I wouldn't dispute their findings as such, actually I suppose their original report would be full of 'if's and 'but's<br /><br />isn't it the case that if once a planet has magnetosphere it keeps it and it keeps it more or less the same strength over its development, so if Mars doesn't have it strong enough today to have kept water how did the water accumulate in the first place uless there were some periods when water bearing comets striked it frequently - but that it perhaps not certain that comets can supply all water for a planet - and if not and Mars developped its indigenous water how could it do that unless it happened at much faster rate than it was being denuded by Sun's action...<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[3488]

It is more likely due to the interior of Mars cooling off & the core at least to stop convecting.<br /><br />The iron contained within is also not spinning independently as it once did.<br /><br />The mantle of Mars is likely mostly solid (there may still be some molten rock), but generally<br />Mars lost its magnetosphere when the iron in the core cooled to a point, that it could no <br />longer maintain a magnetic field.<br /><br />Also when volcanic activity mostly ceased, the atmosphere was no longer maintained, <br />so the solar wind started stripping it away, a process still continuing to this day.<br /><br />Maybe Mars will be without an atmosphere totally in the distant future.<br /><br />Molten iron in motion in a planetary core creates a magnetic field. With Mars this is no longer<br />happening, but it did in its youth.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[vandivx]

sounds right but what is at the bottom of the cooling off of the iron core, I suppose Mars doesn't have quite enough mass to keep its core molten<br /><br />and no wonder when it has roughly just 1/10th of Earth mass but its size is half that of the Earth, it is too big for its mass I suppose to keep the core molten<br /> <br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Yes it is the mass, and the decay of radionucleotides that Mars is lacking in compared to the earth.<br /><br />Hence it cooled much more quickly than the earth. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[yevaud]

Also that lack of mass meant it cooled <i>faster</i> than with the Earth; it had less time to differentiate, which is why there's a goodly proportion of heavier elements present at or near the surface (such as pyrites). <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[3488]

Very true. Whilst Mars is a differentiated planet, the level of that differentiation did not<br />allow for the level of settling of pyrites, etc that has happened in the Earth.<br /><br />This would also explain why Mars may have localised pockets of the former magnetosphere, <br />because the iron that did not sink to the core has kept the record of that time, close or on the surface.<br /><br />IMO, the global magnetosphere of Mars did collapse very early on, perhaps 3.9 - 4 GYA.<br /><br />Whilst the mantle remained molten for far longer asd evidenced by the giant volcanoes, <br />& think the dynamo effect ended far sooner.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[vandivx]

"Hence it cooled much more quickly than the earth."<br />---<br /><br />when you say 'much more quickly'... does that mean that the Earth is also cooling off but at slower rate? I kind of remember it is cooling off a bit year by year and if so what happens first then - life on Earth dies off a) because the Sun becomes cool red giant star one day or b) our atmosphere gets blown away like on Mars after our dynamo stops due to Earth cooling off far enough for the dynamo to freeze up and our magnetosphere goes with it<br /><br />I have always read about life on Earth ending with the Sun going into the red giant phase but then the scientists may not have realized there are other ways we can be threatened like our dynamo ceasing to turn which results in loss of atmosphere<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

Yes, the earth is cooling off but at a MUCH slower rate. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[3488]

Interesting thought.<br /><br />With Earth, only 7% of the internal iron has solidified. Mars cooled off far more quickly <br />than the Earth.<br /><br />Also the Earth has a far greater gravitational pull, which means, that the collapse of the <br />magnetosphere, will probably not strip Earth's atmosphere away so quickly. <br /><br />Venus has no global magnetosphere, but probably has active volcanoes & does have a <br />much stronger surface gravity than Mars (Mars 37% of Earth, Venus 93% of Earth).<br /><br />However, if Venus's volcanoes do cease, the atmosphere will eventually go.<br /><br />With the Earth, time is an issue. In 4.6 GY, only 7% of the iron in the outer core has solidified,<br />by the time enough iron has solidified to completely shut down the magnetosphere,<br />the Sun will have swollen into a red giant, puff out its outer layers & become a white dwarf,<br />not to mention the Milky Way & Andromeda Galaxies merging long before then.<br /><br />The Earth's core solidifying is actually the least of life's worries. An ageing Sun, is a far more pressing<br />issue, as is asteroid & comet impacts.<br /><br />Hope this helps.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[yevaud]

As was already earlier noted in this thread, a further major negative impact of an inactive core is the lack of outgassing via volcanic activity. This is a major mechanism for replacing lost atmospheric species. So no outgassing = atmosphere depletes even faster.<br /><br />One way of making a ballpark estimate of the end of any "dense" atmosphere and possibly free H20 on Mar's surface in the distant past is the age of visible impact craters on the surface. Some are of great age and their endurance to now is indicative of a lack of atmospheric surface processes, lack of Tectonics, and lack of Volcanic activity.<br /><br />Mars lost a substantial amount of it's atmosphere quite a long time ago. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[dragon04]

I believe that's unfortunately true.<br /><br />Maybe just a little more mass with a larger iron core, and things may have been different.<br /><br />At a guess, I'd say that a larger, more dense core might have led to the plate tectonics and magnetosphere that Earth enjoys and provides harborage for life.<br /><br />I don't know if that's random chance, or distance from the Sun, or a combination of the two, though.<br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[yevaud]

Yes, Mars could theoretically have ended up a larger planetary body, had more mass been present when it originally accreted.<br /><br />So a larger mass Mars could well have a decent surface pressure and conditions we could accommodate. Unfortunately, this was not to be. Too many strikes against it from the beginning, I'm afraid. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[3488]

I think that is very true.<br /><br />The core of Mars did solidify a very loooooong time ago. Whilst the volcanic activity lasted until<br />relatively recent times (upto 100 million years ago), the magnetosphere had long gone <br />& the volcanoes could not replenish the atmosphere quickly enough.<br /><br />Of course activity has since waned to virtually zero.<br /><br />The growth of Mars was very likely stunted by Jupiter in its youth, much like to what happened<br />to asteroids 1 Ceres, 2 Pallas & 4 Vesta, although because Mars was further away, Mars<br />did at least acheive full planetary size, although it was caught short of its potential size & mass.<br /><br />It is very true, Mars had far too many strikes in its youth.<br /><br />Despite these short comings, Mars is a most fascinating planet.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[vandivx]

<blockquote><font class="small">In reply to:</font><hr /><p>Venus has no global magnetosphere, but probably has active volcanoes & does have a<br />much stronger surface gravity than Mars (Mars 37% of Earth, Venus 93% of Earth).<br /><br />However, if Venus's volcanoes do cease, the atmosphere will eventually go.<p><hr /></p></p></blockquote><br /><br />that would be great, no more crushing pressure and high temperatures at the surface of Venus would enable us to settle on that planet but I suppose that's way too far off for that to happen, on the other hand when it would happen the atmoshpere might stabilize at some reasonable levels for a long time window due to Venus' pretty good gravitation field... in any case Venus would be habitable for us for a fairly long time before the atmosphere went completely and who knows it might develop some life on its surface on its own in that hospitable period<br /><br />it would appear looking at the Earth that there is quite a leaway for all the different variables to come together in some stable life supporting conditions, I mean if it was too critical then it would be unlikely that even one planet in a star system would be life supporting - unless we are extremely lucky in our solar system<br /><br />it would be immenselly helpfull if we could examine other star planetary system(s) to see how the cards were dealt out elsewhere, I am afraid the first star system we will be able to inspect will have its Venus, Mars, Jupiter and Neptune... like planets but not any near Earthlike, hope such pesimism won't come true<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>